10 Mhz and 1PPS synchronization in a small PCIe form factor

Skydel CDM-5 Clock Distribution Module


Skydel’s CDM-5 clock distribution module is a PCIe card that provides 10MHz and 1PPS signals for up to five devices that need tight and precise synchronization. The clock distribution module is ideal for PCIe-based Software-Defined Radios (SDR) installed in rackmountor desktop PCs, and can also be used for any other applications that require a precise PC-based timing reference.

Key Features

  • Timing and frequency source with 5-way distribution of 10MHz and 1PPS signals
  • PCIe form factor for rackmount or desktop PC
  • Two operating modes: internal clock (OCXO) or external clock (10MHz and 1PPS)
  • Supports standalone operation with 12V DC power supply
CDM-5 Bracket

Two operating modes

Skydel’s CDM-5 clock distribution module features two operating modes—internal or external— that are selected with the bracket-mounted switch.

In internal mode, the CMD-5’s internal clock signal is extracted from the onboard high-grade oven-controlled crystal oscillator (OCXO).
When operating in external mode, CDM-5 accepts input signals in the form of 10MHz and 1PPS, which are then re-distributed via five matched-length traces. Split signals are amplified to maintain the power level across all distributed paths.

Additionally, CDM-5 will regenerate 1PPS from an external 10MHz-only source if a 1PPS source is not available.

CDM-5 Operating Modes Switch

The selection between internal or external mode is achieved through the bracket-mounted switch.

Integrate it in your own design

The CDM-5 clock distribution module can be integrated into a custom assembly simply by removing the bracket plate and powering the board through its 12V DC connector.

When the bracket is removed, the operating mode can be toggled using the onboard switch.

CDM-5 Onboard Switch
CDM-5's onboard switch
SDX GNSS simulator PCIe configuration

A perfect companion to SDX

CDM-5 is perfectly suited to do multiple SDR synchronization. Paired with DekTec DTA-2115B, it enables a compact and powerful PCIe SDX GNSS Simulator configuration.

See all SDX Configurations

CDM-5 Technical Specifications


10MHz input range 0.5...5 V
1PPS input range 2.5...5 V
Connector Type MCX


10MHz 2.5 V
1PPS 5 V
10 MHz output waveform Square wave
1PPS output waveform Logic-level pulse
10 MHz duty cycle 50%
1PPS duty cycle 1%
Time offset between any two 1PPS outputs < 50 ps
Connector Type MCX

Oscillator Performance

Frequency accuracy < 100 ppb
Recommended warm-up time 30 min
Minimum operational warm-up time 5 min
Phase-noise [email protected]
[email protected]
[email protected]

Power Supply

DC Input (PCIe slot or external connector) 12 V
Current consumption < 1 A


Dimensions 11.2 x 6.6 x 2.2 cm
Temperature range 0…50 °C
FCC CertifiedCE Certified

System Architecture

CDM-5 Block Diagram

Photo Gallery


Price per unit: $1,500 USD

Prices exclude applicable sales tax, shipping charges and customs duties. Quantity discounts are available, please request a quotation.


To order a CDM-5, please contact Skydel Sales or one of our value-added resellers. A technical resource can also help you review your needs.

Contact us to order

Additional Resources

Please consult the resources section for the CDM-5 user manual (coming soon) and the CDM-5 datasheet PDF.